a powepoint about the ph scale and acid and akili substinces

cool

1. Ph Scale PowerPoint

2. Defeniton of alkali Alkali are a group of chemicals that contain OH-ion and have a soapy feel. A n example is soap as it’s soapy and it is an alkali T hey are also called bases A lkali is the opposte of an acid

3. Definiton of acid An acid is a chemical substance, usually as liquid, which contains hydrogen. S ome acids burn or dissolve other substances they come into contact with and acidic fruit and drinks are usually have a sour taste or sharp taste. Acid is the opposite of alkali

4. What is a pH indicator pH indicators work by changing colour when they come into contact with certain substances. The y are used to show if a substance is acidic or alkali, or neutral.

5. Some types of pH indicators are R ed and blue litmus paper (blue changes to red if it’s acid, and red changes to blue if it’s alkali) Litmus paper (has a 0 to 14 ph scale) Universal indicator (the same as litmus paper but liquid) The machine pH calculator (the most precise method that can also count in to decimals how much the pH levels are Betroot pH indicator Red Cabbage pH indicator

6. Practicals Making natural indicators: Red cabbage and beetroot Cut them up and mash them up Boil them in water, F ilter them P ut them in to alkali or acid

7. Practical P.2 Making the rainbow Fill up six test tubes with water (to half) Add 7 drops of universal indicator T hen add different amounts of alkali (sodium hydroxie) and acid (hydrochloric acid) See how they change colours to make red to purple

8. Practicals P.3 Testing litmus paper Grab little pieces of litmus paper Try different substances F ind out if they are Acid or Alkali 0 to 6 acid 7 neutral 8 to 14 alkali